Aug_16_1999_L25.txt Shift L25 
        Start at 1999:228:10:00 GMT = 1999 Aug 16 6:00am EDT
        End                           1999 Aug 16 2:00pm EDT

See http://asc.harvard.edu/acis/SOT_reports/sot-shift.html, or 
/proj/ascwww/AXAF/extra/science/htdocs/acis/SOT_reports/Aug_16_1999_L25.txt.
   
SOT Lead	Ed Kellogg
SOT SC/ACA	Rob Cameron
FOT-SI		
HRC-SI		
ACIS-SI		

(Times will be given in GMT on day 228. not precise.)

EVENTS							PLAN	DONE	OBSID
--------------						----	----	-----
Start shift (06am EDT 16 Aug 1999)			1000	1000	1056
Goldstone LOS						1109	1112
Madrid AOS						1720	1645	1056
New OBSID, maneuver, got 2 of 3 acq, 3 of 5 guide stars		1656	1057
New OBSID, maneuver, got 3  acq, 4 of 5 guide stars		1742	1058


End shift (2pm EDT 12 Aug)	day 228			1800	

NOTES/ISSUES/PROBLEMS 
--------------------- 

At H-to-L shift change, 226:1000, 

Chandra	2 hrs before apogee
ACA	tracking, one star box empty
HRC	
EPHIN	nominal
ACIS	
Vacuum 4.5e-6 torr
COM	Goldstone

The shift started quietly. We were in the radiation zone, and went LOS
after 1 hr. We did not see real time data until ~6 hrs later.

Issues being worked:

	* The SOT lead needs a document that gives the correct and
current contents of the daily load in a readable form. We are
discussing implementation with Mission Planning.

	* The M shift needs to make sure that CAP 284 is executed at ~2240 to
disable dither for the ACA Field Distortion Coefficients measurement.

	* Ian Evans is reporting a "poor" aspect solution. We need to
investigate that.

	* Because of stars not acquired in recent pointings, Rob
Cameron will be analyzing the data to see if any trend emerges for the
disparity between stellar receiver magnitudes in the OFLS catalog and
those observed in ACA, vs. color, time, etc. It appears that the
receiver magnitudes are ~1 mag fainter than the catalog
magnitudes. The fidlites do not appear to be changing with time, so
that probably obviates camera icing as the cause.

	* We need to make a permanent change in the algorithm for
generating the DOT so that there will be a 3 min delay between ACIS
stop science (AA00000000) and commanding the next OBSID, to allow ACIS
to send down data that are transmitted after AA00000000 but belong
with the previous obsid. This was communicated to CXC MP, Pat Slane.


The maneuver at 1656 got 2 of 3 acquisition stars, and 3 of 5 guide
stars, a bit worse than the previous maneuvers. We continue with
another Crude Optical Axis Determination ACIS observation, at y_offset
= 2.8', z_offset = 2.8.'